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Polycyclic Aromatic Hydrocarbons and Their Remediation by Biochar
The distribution of polycyclic aromatic hydrocarbons (PAHs) around the world is influenced by anthropogenic, natural, and global transport activities. They are pervasive environmental contaminants that are toxic, mutagenic, carcinogenic, and have negative biological effects. PAH molecules stability and hydrophobicity are the two main factors that influence their long-term persistence in the environment. PAHs contamination of soil, water and sediments has been widely dissipated for years, necessitating effective remediation processes through research and development to achieve impactful treatment and reuse of soil, water and sediments. The biochar amendment to PAHs contaminated soil, water and sediments has been suggested as an inventive and environmentally friendly technology. The primary method of removing PAHs involves sorption onto biochar. In this chapter, types and effects of PAHs exposure on humans the mechanisms of PAH sorption to the biochar, effects of adding biochar to soil, water and sediments that have PAH contamination are thoroughly discussed. 2025 The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG. -
Polycyclic Aromatic Hydrocarbons in the Circumstellar Medium of Herbig Ae/Be Stars
We present a comprehensive mid-infrared spectroscopic survey of 124 Herbig Ae/Be stars using newly processed Spitzer/IRS spectra from the newly released CASSISjuice database. Based on prominent dust and molecular signatures (polycyclic aromatic hydrocarbons (PAHs), silicates, and hydrogenated amorphous carbons), we classify the stars into five groups. Our analysis reveals that 64% of the spectra show PAH emission, with detections peaking in the stellar effective temperature range 7000-11,000 K (B9-A5). Silicate features appear in 50% of the sample and likewise diminish at higher temperatures. Additionally, we find that future PAH studies can focus on Herbig Ae/Be stars with a spectral index n2?24 > ?1 and flared morphologies to maximize PAH detections. The 6.2 ?m PAH band is the most frequently observed in our sample, shifting blueward with increasing stellar temperature, and this is the largest sample yet used to test that peak shift. The weaker 6.0 ?m feature does not shift with 6.2 ?m, implying a distinct origin of C=O (carbonyl) or olefinic C=C stretching relative to C-C vibrations. We examined the 11.0/11.2 ?m PAH ratio using high-resolution Spitzer spectra for the first time in a sample of Herbig Ae/Be stars, finding a range of ionization conditions. This study provides a strong foundation for future JWST observations of intermediate-mass pre-main-sequence stars. 2025. National Astronomical Observatories, CAS and IOP Publishing Ltd. All rights, including for text and data mining, AI training, and similar technologies, are reserved. -
Polycystic Ovary Syndrome Diagnosis: The Promise of Artificial Intelligence for Improved Clinical Accuracy
PCOS is an endocrine illness that affects 610% of women worldwide. It can cause a variety of symptoms, including irregular menstruation periods, ovarian cysts, and hyperandrogenism. Its lack of defined biomarkers, overlapping symptoms, and heterogeneity make diagnosis difficult. By studying hormone profiles, identifying patterns difficult to see with conventional approaches, and offering great precision and accuracy, AI and ML techniques are transforming diagnostic difficulties. Hybrid models in the list include SWISS-AdaBoost and ensemble learning techniques that have accuracies up to 98% enabling early diagnosis along with appropriate treatment strategies. Early detection by technologies such as AI will prevent significant health complications that are PCOS-related, such as infertility, type II diabetes, or cardiovascular diseases. This study depicts the transformative role of the application of AI in diagnosing cases of PCOS and highlights the possibility of facilitating clinical decision-making, reducing potential diagnostic delays, and enhancing improvements in patient outcomes. Future research should hence be directed towards the establishment of AI within healthcare with consideration of validation, reliability, and ethical considerations to maximize its use in clinical practice. 2025 Oriental Scientific Publishing Company. All rights reserved. -
Polycystic ovary syndrome: An exploration of unmarried women's knowledge and attitudes
Polycystic Ovary Syndrome (PCOS) is a common endocrine disorder among women of reproductive age and a chief cause of subfertility attributed to ovulation. Besides, lack of knowledge about PCOS, its treatment, and lifestyle changes influence the prognosis. The present qualitative inquiry investigates the knowledge and attitudes of unmarried women towards the syndrome, associated treatment, and necessary lifestyle changes in the fight against the same. A total of 15 participants with PCOS were selected using purposive sampling (n from southern parts of India viz. Kerala and Tamil Nadu states. The telephonic interviews were conducted in late November and early December 2020. He conventional content analysis emerged with six major themes. The themes capsulated women's knowledge, causes, complications and risk factors, treatment of PCOS their perceived importance of health promotive behaviours such as physical activity, sleep patterns, and perceived support from society. The importance of diet, exercise and a healthy lifestyle were additional relevant factors stressed by the respondents. Although the medicines helped participants attain regular menstrual cycles, they also had side effects reported in the discussion. Few respondents reported that they lacked the necessary awareness of PCOS when diagnosed at a younger age. The study enhances the understanding of PCOS from a qualitative approach that has cultural relevance apart from pertinent clinical and lifestyle implications. 2022 The Author(s) -
Polyhydroxyalkanoate biosynthesis and characterization from optimized medium utilizing distillery effluent using Bacillus endophyticus MTCC 9021: a statistical approach
Use of expensive raw material and inefficient extraction method has limited the production of biopolymers at pilot scale compared to commercial plastics. Hence, this research work spotlights on production of polyhydroxyalkanoate (PHA) using Bacillus endophyticus MTCC 9021 in different dilutions of untreated distillery effluent (1025%) among which 10% dilutions exhibited maximum PHA production. Statistical optimization through Response surface methodology yielded a maximum PHA of 6.45 0.07 g/L. The obtained PHA was analysed by FTIR and NMR which confirms the polymer to be polyhydroxybutyrate. The extracted PHA was reduced to nanoscale to develop PHA nanosheet which exposed higher oil absorption and retention ability than normal PHA sheet. Further the rapid degradation of PHA nanosheet with synthetic plastics in garden soil emphasises their unique application in wide sectors. 2020, 2020 Informa UK Limited, trading as Taylor & Francis Group. -
Polyhydroxyalkanoates as potential tools for denitrification of wastewater
Denitrification is the main process in water and wastewater treatment which plays the critical role in mitigating nitrate contamination and ensuring environmental and public health safety. Introduction of polyhydroxyalkanoates (PHA) in water treatment systems enables widening of its application in denitrification processes. Emphasising the importance of denitrification in water treatment helps to prevent the surge of nitrate concentrations, thereby hindering eutrophication and maintaining the balance of aquatic ecosystems. Therefore, there is an increasing urgency for the development of sustainable and efficient denitrification techniques to address contemporary challenges in water quality management. PHAs are produced by a variety of microorganisms under limited nutritional conditions and present themselves as promising candidate for denitrification due to their favourable characteristics which include biocompatibility, biodegradability and ability to store carbon and energy. The current chapter delves with the mechanisms governing denitrification employing PHA along with the intricate biochemical pathways and metabolic processes involved. PHA serves a dual role as both a carbon source and an electron donor in denitrifying bacteria, aiding in the conversion of nitrate to nitrogen gas in anaerobic environments. The chapter furthermore addresses various factors such as substrate availability, microbial community composition, and environmental parameters which are affecting the efficiency of PHA-mediated denitrification. Despite the potential advantages, challenges impede the widespread adoption of PHA in denitrification processes. Technical constraints such as substrate availability, yield of PHA and reactor design, coupled with economic factors such as production costs, present significant barriers. Future research endeavours should prioritise optimising processes, surmounting technical and economic hurdles, and comprehending the ecological ramifications for water and wastewater treatment systems using PHA. Springer Nature Singapore Pte Ltd. 2025. All rights reserved. -
Polymer Nanocomposite Graphene Quantum Dots for High-Efficiency Ultraviolet Photodetector
Influence on photocurrent sensitivity of hydrothermally synthesized electrochemically active graphene quantum dots on conjugated polymer utilized for a novel single-layer device has been performed. Fabrications of high-performance ultraviolet photodetector by depositing the polypyrrole-graphene quantum dots (PPy-GQDs) active layer of the ITO electrode were exposed to an Ultraviolet (UV) source with 265 and 355 nm wavelengths for about 200 s, and we examined the time-dependent photoresponse. The excellent performance of GQDs was exploited as a light absorber, acting as an electron donor to improve the carrier concentration. PGC4 exhibits high photoresponsivity up to the 2.33 A/W at 6 V bias and the photocurrent changes from 2.9 to 18 A. The electrochemical measurement was studied using an electrochemical workstation. The cyclic voltammetry (CV) results show that the hysteresis loop is optically tunable with a UV light source with 265 and 355 nm at 0.1 to 0.5 V/s. The photocurrent response in PPy-GQDs devices may be applicable to optoelectronics devices. 2022 by the authors. -
Polymer photosupercapacitors: combined nanoarchitectonics with polymer solar cell and supercapacitor for emerging powerpacks in next-generation energy applications
Efficient energy harvesting and storage are inevitable for the sustenance and growth of mankind, wherein the utilization of advanced technologies in this field has brought a significant impact on the energy sector. Integration of energy harvesting and storage devices is a need for powering next-generation energy needs like the Internet of Things (IoT), opening a wide range of application areas like wearable devices or integration with fabrics. Among third-generation solar cells, organic or polymer solar cells are extremely environment-friendly, lightweight, and flexible, making themselves potential candidates for integrated powerpacks along with supercapacitors. This article is a comprehensive review of polymer solar cell-based photosupercapacitors and their developments over the recent years. Through this review, we intend to give a valid account of polymer photosupercapacitors, to the scientific community regarding recent updates, which would help develop future approaches and strategies. As these integrated devices are considered to have a profound impact on energy industries and related applications, we believe that a detailed review of the present status and future prospects would aid further developments in the research field. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2024. -
Polymer-Based Nanomaterial as a Bacteriostatic Agent on Gram-Positive Bacteria
The colonization of surfaces by bacteria is a widespread phenomenon that affects environmental processes and human health. Bacterial growth can also be found in materials used in the textile industries, food packaging, and wearable electronics. Moreover, the necessity for replacing traditional antibiotics is relevant due to the increased health risks of antimicrobial resistance from the excessive use of antibiotics. Recently, research is focused more on developing polymer-based antibacterial materials critical to preventing bacterial proliferation. The use of some nanomaterials appears to be very promising in this regard. This work reports the synthesis of a polymer-based nanomaterial derived from polyvinyl alcohol (PVA) via the hydrothermal method and studies its structural and optical properties. It is also observed that these nanoparticles (NPs) display the highest antibacterial potency against gram-positive (Bacillus subtilis) bacteria than their bulk counterpart. 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. -
Polymer-Carbon nanocomposite: Synthesis, optical and biocidal properties
Microorganism contamination of food storage, water treatment, pharmaceuticals, and especially biomedical equipment is a severe problem. Bacteria frequently contaminate permanent implantations after long-term usage. To successfully treat these infections, it is essential to monitor microbial activity and know how it interacts with antibodies in real-time. In this work, a nanocarbon-polymer nanocomposite (ARPD) is successfully developed, and its antibacterial activity against selected microorganisms is successfully validated. Obtained antibacterial results confirm that the photoluminescent ARPD demonstrated outstanding antibacterial action against the microorganism Escherichia coli from the selected group of bacteria. The fluorescent diagnostics and treatments offer exciting possibilities for the luminescence and biocidal activity of nanocomposite produced from ARH-PVDF nanomaterials. 2023 The Author(s) -
Polymer-nanocarbon composites: a promising strategy for enhanced performance of organic solar cells
The exigency for sustainable and clean energy resources has led to profound research in development of various generations of solar cells, aiming to control the over-exploitation of fossil fuels and subsequently limit environmental degradation. Among the fast-emerging third-generation solar cells, polymer solar cell technology has gained much consideration due to its potential for achieving economically feasible, lightweight, flexible solar energy harvesting devices. As a predominant research area, at present, the major concerns regarding polymer solar cells include improving conversion efficiency, enhancing absorption bandgap in polymers, limiting photochemical degradation, and remediating low dielectric constant. Nanocarbon materials can be effectively blended with polymers and have been widely reported to enhance the performance of polymer solar cells owing to their desirable characteristics like high electrical conductivity, mechanical strength, thermal stability, non-toxicity, large specific surface area, flexibility, and optical transparency. In this review, we briefly discuss various conjugated polymer-nanocarbon composites, including polymer/graphene derivatives, polymer/graphene quantum dots (GQD), and polymer/carbon nanotubes (CNTs), elucidating their roles in the performance enhancement of polymer solar cells (PSCs). Graphical abstract: (Figure presented.). The Author(s) 2023. -
Polymeric Nanocomposites and Their Applications
A polymer is a macromolecule comprising numerous repeating subunits linked by covalent bonds. The word polymer arises from Greek, with polus denoting many and meros denoting parts. Although humans have used polymers long before, their chemical properties were studied only in the nineteenth century. The Author(s), under exclusive license to Springer Nature Switzerland AG 2025. -
Polynomial time algorithm for inferring subclasses of parallel internal column contextual array languages
In [2,16] a new method of description of pictures of digitized rectangular arrays is introduced based on contextual grammars, called parallel internal contextual array grammars. In this paper, we pay our attention on parallel internal column contextual array grammars and observe that the languages generated by these grammars are not inferable from positive data only. We define two subclasses of parallel internal column contextual array languages, namely, k-uniform and strictly parallel internal column contextual languages which are incomparable and not disjoint classes and provide identification algorithms to learn these classes. Springer International Publishing AG 2017. -
Polynomial time learner for inferring subclasses of internal contextual grammars with local maximum selectors
Natural languages contain regular, context-free, and context-sensitive syntactic constructions, yet none of these classes of formal languages can be identified in the limit from positive examples. Mildly context-sensitive languages are capable to represent some context-sensitive constructions such as multiple agreement, crossed agreement, and duplication. These languages are important for natural language applications due to their expressiveness, and the fact that they are not fully context-sensitive. In this paper, we present a polynomial-time algorithm for inferring subclasses of internal contextual languages using positive examples only, namely strictly and k-uniform internal contextual languages with local maximum selectors which can contain mildly context-sensitive languages. 2017, Springer International Publishing AG. -
Polyoxometalate/?-Fe2O3/polyaniline composite: Tailored approaches for high-performance supercapacitors
The need for portable, high-performance electronics that have high power or energy density has increased significantly in recent years. In this work, a composite material was coated on stainless steel that consists of polyoxometalate (POM)/?-Fe2O3/polyaniline (PANI) as an electrode material for a symmetric supercapacitor. ?-Fe2O3 was prepared using starch as a template while PANI was electrodeposited. The physical and chemical characteristics of the modified electrodes were investigated via Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and electrochemical techniques such as cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge[sbnd]discharge (GCD) experiments. In 1 M H2SO4, the composite had a specific capacitance of 528 F/g at a current density of 0.2 A/g. In addition, the composite exhibited a high energy density of 73.4 Wh kg?1 at a high-power density of 7.14 kW kg?1 and 91.62 % capacity retention after 10 cycles. The results show that POM/?-Fe2O3/PANI is a promising composite electrode for use as a supercapacitor electrode material. 2024 The Authors -
Polyoxometalate/?-Fe2O3/polyaniline composite: Tailored approaches for high-performance supercapacitors
The need for portable, high-performance electronics that have high power or energy density has increased significantly in recent years. In this work, a composite material was coated on stainless steel that consists of polyoxometalate (POM)/?-Fe2O3/polyaniline (PANI) as an electrode material for a symmetric supercapacitor. ?-Fe2O3 was prepared using starch as a template while PANI was electrodeposited. The physical and chemical characteristics of the modified electrodes were investigated via Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and electrochemical techniques such as cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge[sbnd]discharge (GCD) experiments. In 1 M H2SO4, the composite had a specific capacitance of 528 F/g at a current density of 0.2 A/g. In addition, the composite exhibited a high energy density of 73.4 Wh kg?1 at a high-power density of 7.14 kW kg?1 and 91.62 % capacity retention after 10 cycles. The results show that POM/?-Fe2O3/PANI is a promising composite electrode for use as a supercapacitor electrode material. 2024 The Authors -
Polyoxometalates and redox-active molecular clusters for supercapacitors
Hybrid electric vehicles and portable electronic devices become inevitable part of our daily life and it is necessary to develop efficient energy storage devices to supply them power. Supercapacitors (SCs) are electrochemical energy storage devices with high power densities. The electrochemical performances of a SC depend mainly on the electrode-active material used in it. An efficient electrode-active material should have qualities such as large surface area, porous structure, uniform pore distribution, good chemical and electrochemical stabilities, and good mechanical strength, to name a few. Mesoporous electrode architecture is highly preferred to obtain maximum electrolyte-ion accessibility that can boost the electrochemical performance of the SC electrode. The various electrode-active materials developed to date are transition metal oxides, electronically conducting polymers, carbon nanomaterials, etc. Polyoxometalates (POMs) are comparatively novel electrode candidates that possess excellent structural stability during the reversible redox reactions. A unique characteristic such as higher oxidation state possessed by POMs makes them an ideal platform to accept and release electrons during the electrochemical charge storage. POMs are considered to be a polyatomic anion, which hold early transition metals like Mo, V, W, etc., and are linked to an oxygen atom in a three-dimensional cluster. The cluster formation of POMs enables higher stability and easy to prepare composites with other materials such as carbon nanomaterial, electronically conducting polymers, etc. The preparation of hybrid electrode architectures by anchoring of POMs helps in producing a large number of electroactive sites for the enhanced electrochemical reactions to occur. This chapter explains the salient features and functionalities of POMs and redox-active molecular clusters that affect the SC performance. 2024 Elsevier Inc. All rights reserved. -
Polyphenol composition and antioxidant activity of andrographis paniculata L. nees /
Mapana Journal of Sciences, Vol.13, Issue 4, pp.481-494, ISSN No: 0975-3303 (Print) -
Polypyrrole functionalized MoS2 for sensitive and simultaneous determination of heavy metal ions in water
Assessing heavy metal ion (HMI) contamination to sustain drinking water hygiene is a challenge. Conventional approaches are appealing for the detection of HMIs but electrochemical approaches can resolve the limitations of these approaches, such as tedious sample preparation, high cost, time consuming and the need for trained professionals. Here, an electrochemical approach is developed using a nano-sphered polypyrrole (PPy) functionalized with MoS2 (PPy/MoS2) by square wave anodic stripping voltammetry for the detection of HMIs. The developed sensor can detect Pb2+ with a limit of detection of 0.03 nM and a sensitivity of 36.42 ?A nM?1. Additionally, the PPy/MoS2 sensor was employed for the simultaneous detection of HMIs of Cd2+, Pb2+, Cu2+ and Hg2+. The reproducibility, stability and anti-interference studies confirm that the sensor can be used to monitor HMI contamination of water. 2025 The Royal Society of Chemistry. -
Polypyrrole functionalized MoS2 for sensitive and simultaneous determination of heavy metal ions in water
Assessing heavy metal ion (HMI) contamination to sustain drinking water hygiene is a challenge. Conventional approaches are appealing for the detection of HMIs but electrochemical approaches can resolve the limitations of these approaches, such as tedious sample preparation, high cost, time consuming and the need for trained professionals. Here, an electrochemical approach is developed using a nano-sphered polypyrrole (PPy) functionalized with MoS2 (PPy/MoS2) by square wave anodic stripping voltammetry for the detection of HMIs. The developed sensor can detect Pb2+ with a limit of detection of 0.03 nM and a sensitivity of 36.42 ?A nM?1. Additionally, the PPy/MoS2 sensor was employed for the simultaneous detection of HMIs of Cd2+, Pb2+, Cu2+ and Hg2+. The reproducibility, stability and anti-interference studies confirm that the sensor can be used to monitor HMI contamination of water. 2025 The Royal Society of Chemistry.